Press
The Technology

DARC — Duration Adjusted
Return on Capital

A fixed income-derived framework that replaces IRR with a duration-consistent forward yield — enabling risk-neutral performance measurement, time transferability, and aggregation-consistent index construction for private capital.

USPTO Patent US 8,386,356 B2
JP Patent No. 6014124
SG Patent No. 194993
Journal of Portfolio Management — Peer Reviewed

The Problem with IRR

Private capital has never had a true time-weighted return.

The Internal Rate of Return has been the dominant performance metric in private capital for decades. It solves a nonlinear discounting equation, implicitly assuming reinvestment of interim distributions at the IRR itself — a circular, unrealistic assumption that prevents meaningful cross-asset comparison.

PME measures introduce external market discounting but do not produce time-weighted returns consistent with other asset classes. No existing measure resolves the three structural challenges of private capital: risk-neutrality, time transferability, and aggregation-consistent indexing.

IRR Limitation
Embeds its own discount rate — implying reinvestment at the IRR itself. Circular, not comparable across asset classes, and cannot be transferred along a term structure.
PME Limitation
Ratios are not additive across funds or time periods. Cannot be used to build aggregation-consistent indices or multi-period composites.
Modified Dietz
Despite being labelled time-weighted in some guidance, it is a first-order approximation of IRR and inherits its reinvestment circularity.

The DARC Framework

A forward yield extracted from duration-equivalent bullet representations of fund cash flows.

DARC applies Macaulay duration — the weighted average time of a financial transaction — to private fund contributions, distributions, and NAVs. Each cash flow stream is replaced with a single equivalent bullet payment located at its respective duration. The forward yield between the two bullets is DARC.

DARC = ( BD / BI )1/Δ − 1
Where Δ = DD − DI is the net duration interval between distribution and contribution bullets. BD and BI are the equivalent bullet values at their respective durations.

DARC operates within the arbitrage-free term structure theory of Heath, Jarrow and Morton. It uses an exogenous risk-free discount curve — not its own rate — decoupling performance measurement from reinvestment assumptions entirely. The result is a compounded forward yield over the net duration interval: the constant annualised rate at which the contribution bullet must grow to equal the distribution bullet.

Three Foundational Properties

What elevates DARC from an alternative metric to a unifying framework.

01

Risk-Neutral Yield Transfer

DARC enables arbitrage-free yield transfer along the term structure — a capability absent from all existing private capital performance measures. Two funds with different duration profiles can be compared at any common horizon without distorting their economic content.

02

Notional Preservation

Undrawn commitments are treated as a synthetic risk-free position, directly solving the problem of measuring returns on partially deployed capital. Investors are exposed to the full commitment from inception — DARC accounts for this explicitly.

03

PV-Space Aggregation

DARC is aggregation-consistent in present-value space — the structural requirement for index construction. The aggregated DARC is derived from pooled bullets, not from averaging individual fund rates. This property no other private capital measure possesses.


From J-Curve to S-Curve

Duration marks the inflection point where increasing marginal returns begin to diminish.

The traditional J-Curve captures the early negative returns of private fund investing followed by eventual gains. DARC replaces this with the S-Curve: a more accurate model that incorporates the inflection point — the duration — where increasing marginal returns plateau and then decline.

The S-Curve enables daily NAV monitoring through statistical estimation of expected valuations and probabilistic adjustment of reported figures — without discarding accounting data. Real-time fair valuation monitoring becomes structurally possible for the first time.

Core Return
The forward yield on drawn capital over the net duration interval. Free of reinvestment circularity — placed on the calendar where and when performance actually accrues.
Notional-Preserving DARC
Extends the forward yield to cover total committed capital, including undrawn balances treated as a synthetic risk-free position maturing at the fund's distribution horizon.
Time Transfer
Any DARC-derived rate can be transferred to any target maturity T* — just as bond yields are standardised to comparable maturities — enabling like-for-like comparison and multi-asset integration.
Horizon Return
Reconciles the model with actual cash availability daily. Enables unambiguous settlement terms, synthetic replicability, and recording of daily private market returns.

Read the full technical framework in the latest SSRN working paper, or explore the JPM peer-reviewed publication.

SSRN Working Paper → JPM Article →